Wire stretcher



July 11, 1939. H. J. CAMPBELL vWIRE STRETCHER Filed July 28, 1937 2 Sheets-Sheet 1 July 11, 1939. CAMPBELL 2,165,695

WIRE STRETCHER Filed July 28, 1937 V 2 Sheets-Sheet 2 Campbell Summer Patented July 11, 1939 UNITED STATES PATENT OFFICE WIRE STRETCHER Harry J. Campbell, Woodworth, Mont.

Application July 28, 1937, Serial No. 156,163

2 Claims.

.My present invention relates to improvements in wire stretchers of the block and tackle type, by means of which a wire may be tightly clamped and stretched taut with safety and without danger of bruising or marring the wire, and without danger of bending or breaking the wire due to the action of the clamped jaws. The wire stretcher or pulling implement is of the type employingpivoted or hinged jaws, one of which is separable from the other for the purpose of inserting or introducing the wire to be pulled into the implement.

The pulling implementis readily adaptable for use with various kinds of wire, as for instance fence wires, electric transmission wires etc., and means are provided in the implementwhereby the clamp jaws may readily be adapted for pulling or stretching taut wires of different sizes.

In carrying out my invention I provide the clamp jaws with comparatively long clamp faces that are frictionally clamped against comparatively long stretches of the wire so that the strain of the pull is distributed over the clamped stretch of wire throughout the length of the clamp or gripping faces, thus avoiding the danger of breaking that accompanies the grip of the wire at a single point. This feature of applying a long grip to the clamped wire, I am enabled to employ on the various sizes of wires to be-clamped, due to the use of an adjustable pin or pivot connecting the jaws, by means of which adjustable pin the space between the gripping faces of the clamping jaws is varied to accord with the size of. the wire, andw is at the same time the opposing friction faces of the jaws are maintained in parallelism.

The invention consists in certain novel combinations and arrangements of parts as will hereinafter be more fully set forth and claimed. In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention wherein the parts are combined and arranged in accord with one mode I have thus far devised for the practical application of the principles of my invention. Various changes and alterations may be made in these exemplifying structures within the scope of my claims without departing from the principles of my invention.

In the drawings:

Figure 1 is a view in side elevation showing the pulling implement or wire stretcher of my invention in operation.

Figure 2 is an enlarged perspective view of the separable jaws in closed position.

Figure 3 is a detail perspective view of the adjustable hinge pin for the two jaws.

Figure 4 is an enlarged detail view partly in section showing the manner of supporting the adjustable hinge pin in one of the jaws.

Figure 5 is a view in perspective of one of the jaws showing the use of a removable and re- 5 placeable gripping pad used especially when wire of soft material is being stretched.

Figure 6 is a transverse sectional view at line 6--6 of Figure 5.

Figure 7 is a detail sectional view at line 'l---! 10 of Figure 4.

Figure 8 is a perspective view showing the separable clamp jaw separated from the other jaw.

In carrying out my invention the wire as W is clamped between the comparatively long clamp 15 jaws l and 2, which as indicated in Figure 1 are slightly curved to accommodate the dangling end of the wire, and the jaw 2 is separable from the jaw I for the purpose of introducing orinserting v the wire in the implement. The jaws are com- 0 pressed one against the other, or clamped, through the use of a pair of lever arms 3 and l integral with the jaws l and 2, and these arms diverge as'shown in order to provide for the required leverage that insures a tight clamp on the 25 wire throughout the entire length of the two gripping faces of the jaws. The free ends of the lever arms are provided with clevises 5, 5 and eyes '6, 6, for attachment of the two short chains 1 and 8, and the coupling ring 9 of these chains 30 is employed for connection to the block and tackle indicated as a whole by the numeral lilin Figure 1. It will be apparent that a pull in usual manner on the block and tacklewill cause the two jaws to be clamped together against the 35 wire W, and the frictional engagement between the gripping faces of the jaws and the wire extends throughout the length of these faces.

In some instances the gripping faces may be transversely corrugated, as at la in Figure 4 to 40 increase the frictional engagement of the gripping faces with the wire W, and in any event the long gripping faces provide for a wide distribution of the pulling strain throughout the whole stretch of clamped wire, thus avoiding the 45 danger of breaking that is ever-present when the strain is applied only at a single point in the length of the wire.

A best seen in Figure 4, the jaw l at its forward endis fashioned with two spaced ears I2 and I3, 50 one of which is fashioned with a socket opening l4 and the other with a bolt hole 15, and these ears are provided for the support of the hinge pin or pivot pin I6 which extends transversely of the jaws. 55

The hinge pin as shown in Figure 3 is provided with an angular head l1, here shown as octagonal, which is adapted to fit into the socket I4 that also is provided with octagonal sides. See Figure 2. At its opposite end the pin is provided with a threaded bolt portion l8 that is adapted to pass through the bolt hole [5, and a shoulder is thus formed at the end of the pin for engagement with the inner face of the ear l2, so that, when a nut l9 threaded on the protruding end of the bolt 18 is turned home the pin is tightly clamped in its supporting ears. The hinge pin is adjustable on its longitudinal axis by means of the eccentric relation of the bolt l8 to the pin as best seen in Figure 3, so that the two gripping faces of the jaws may be adjusted to different sizes of wire. The octagonal socket I4 is larger than the octagonal head I! to provide for the different position of the head as the pin is adjusted toward or' away from the gripping face of the jaw l, and therefore the pin may be turned on its axis to desired position and secured by the nut 19in adjusted position, to form a bearing for the separable jaw 2.

The separable jaw 2, which is detached from jaw I before the wire W is laid on the gripping face of jaw l, is fashioned with two spaced semicircular front hooks 20, spaced apart to form a notch or eye 2| for the wire, and at the outer sides of these hooks the jaw is formed with shoulders 22, which shoulders accommodate the ears l2 and I3 of the jaw l.

After the wire is placed in position, the separable jaw is hooked over the hinge pin with the notch 2| straddling the wire, and then the two gripping faces of the jaws are brought into contact with the wire. A pull on the wire through the use of the block and tackle in usual manner clamps the gripping faces against the wire.

The gripping faces are maintained at all times in true parallelism, regardless of the thickness of the wire, due to the use of the rotatable adjustable hinge pin on which the hooks have their bearings. In clamping a thin wire the gripping faces are spaced a minimum distance apart. To increase this space for the accommodation of a thicker wire and still maintain the parallelism of the gripping faces, the hinge pin is turned so that the bearing of the hooks on the pin is brought nearer to the gripping face of jaw l, and of course the pin may be turned, step by step, to vary the size of the space between the gripping faces.

In some instances when the wire is made of soft material, as copper and there is danger of marring the wire, I may employ removable and. replaceable friction pads of suitable material, as rubber, asbestos, and similar material. For this purpose, the jaw 23 of Figure 5 is provided with a dovetail groove 24 in its gripping face, and a tongue or tenon 25 having the gripping pad 26 fastened or attached thereto in suitable manner, is slipped into the dovetail groove and there held by friction. Bothof the gripping faces of the clamping jaws may be provided with these gripping pads, and as the pads conform to the curvature of the two parallel jaw-faces, the pads themselves present parallel frictional faces for engagement with the wire W throughout the length of the gripping jaws.

If the implement is used on the free end of a wire, the free end of the wire may be inserted between the jaws while the separable jaw is in place, and so also, this free end of the wire may be withdrawn from. the implement after the wire has been stretched and anchored, without necessity for removing the separable jaw. When the device is to be applied to the wire at an intermediate point in its length, the jaw 2 is first swung on its hinge pin over in front of the jaw l to permit withdrawal of the hooks from the pin for the purpose of separating the jaws. After the jaw I is placed in position under the wire, the separated jaw is first hooked on its pin and then swung back intoparallelism with the other jaw 2 and the device is ready for use.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a wire stretcher of the block and tackle type, the combination of a pair of jaws having outwardly diverging lever arms, one of said jaws having a pair of spaced ears one of which is fashioned with an angular socket and the other ear fashioned with an eccentrically arranged bolthole, of an adjustable hinge pin having an angular head seated in the socket and an eccentric bolt-end passed through said bolt hole, a clamp nut on the free end of the bolt-end, the other jaw having a pair of spaced hooks forming a wire-slot between them, and said hooks having bearings on said pin between the spaced ears.

2. In a wire stretcher of the block and. tackle type, the combination of a pair of jaws having diverging lever arms, removable gripping pads mounted in said jaws and means for retaining said pads in the jaws, one of said jaws having a pair of spaced cars, a cylindrical hinge pin mounted in one of the ears, an eccentric-bolt end on said pin and mounted in a bolt hole in the other ear and a clamp nut on the free end of the bolt-end, a pair of spaced semicircular hooks on the other jaw and forming between them a wireslot, and said hooks having bearings on said pin between the spaced ears.

HARRY J. CAMPBELL. 

